Rickettsiosis: existing advances and future opportunities for the development of vaccines.

Rickettsioses is a zoonotic disease caused by an intracellular bacterium transmitted through the bites of hematophagous arthropods. While antibiotics can effectively treat this disease, overuse may lead to the development of antibiotic resistance. To combat this issue, vaccine development has been pursued to address this bacterial infection. The types of vaccines formulated against Rickettsia include inactivated, live-attenuated, subunit, DNA, and nanovaccines, all of which induced immune responses, and some demonstrated protective efficacy against infectious challenges. These outcomes have encouraged new scientific efforts to develop vaccines against rickettsiosis. Therefore, this review focuses on describing Rickettsia classification, transmission, pathogenesis, and immune evasion, followed by a discussion of advancements in vaccine development against Rickettsia, detailing the antigens, synthesis and production, formulations, immunization, delivery strategies, and protective efficacy. Additionally, challenges for Rickettsia vaccines were identified and placed in perspective as future opportunities.